[Analysis of population attributable risk of large for gestational age].

Objective: To examine the association of pre-pregnancy obesity, excessive gestational weight gain (GWG) and gestational diabetes mellitus (GDM) with the risk of large for gestational age (LGA), and assess the dynamic changes in population attributable risk percent (PAR%) for having these exposures. Methods: A retrospective cohort study was conducted to collect data on pregnant women who received regular health care and delivered in Beijing Obstetrics and Gynecology Hospital from January to December in 2011, 2014 and 2017, respectively. Information including baseline characteristics, metabolic indicators during pregnancy, pregnancy complications, and pregnancy outcomes were collected. Multivariate logistic regression model was constructed to assess their association with LGA delivery. Adjusted relative risk and prevalence of these factors were used to calculate PAR%and evaluate the comprehensive risk. Results: (1)The number of participants were 11 132, 13 167 and 4 973 in 2011, 2014 and 2017, respectively. Corresponding prevalence of LGA were 15.19% (1 691/11 132), 14.98% (1 973/13 167) and 16.21% (806/4 973). No significant change in the prevalence of LGA was observed across all years investigated (all P>0.05). (2)According to results from multivariate logistic regression model, advanced maternal age, multiparity, pre-pregnancy overweight or obesity, GWG,GDM and serum triglyceride level≥1.7 mmol/L in the first trimester were associated with high risk of LGA (all P<0.05). Among these factors, pre-pregnancy overweight or obesity, excessive GWG and multiparity were common risk factors of LGA. GDM was not associated with risk of LGA in 2017 database. (3) Dynamic change of PAR% in these years were notable. PAR% of GWG for LGA decreased (32.6%, 27.2% and 22.2% in 2011, 2014 and 2017, respectively), while PAR% of pre-pregnancy overweight or obesity showed an upward trend (4.2%, 3.3% and 8.4%). In addition, PAR% of multiparity increased as well (3.5%, 6.3% and 15.9%). (4) Further analysis showed that excessive GWG in the first and second trimesters contributed the most (20.2% and 19.0% in 2014 and 2017). Conclusions: Excessive GWG, pre-pregnancy overweight or obesity and multiparity are the important risk factors what contribute to LGA. PAR% of excessive GWG for LGA decrease in recent years. However, GWG in the first and second trimesters is a critical factor of LGA. Appropriate weight management in pre-pregnancy, the first or second trimester is the key point to reduce the risk of LGA.目的： 评价在不同年度发生大于胎龄儿（LGA）的相关因素，包括妊娠前肥胖、妊娠期增重过多、妊娠期糖尿病（GDM）等对LGA发生的人群归因危险度百分比（PAR%）的影响。 方法： 采用回顾性队列研究的方法，收集2011年1月至12月、2014年1月至12月及2017年1月至12月于北京妇产医院行规律产前检查并分娩的单胎孕妇的临床资料，包括一般情况、妊娠期糖脂代谢水平、并发症及妊娠结局；建立多因素回归模型，并结合相关人群发生率计算PAR%，评价各因素对LGA发生的影响及其变化趋势。 结果： （1）2011、2014及2017年度分别纳入单胎孕妇11 132、13 167及4 973例，LGA的发生率分别为15.19%（1 691/11 132）、14.98%（1 973/13 167）及16.21%（806/4 973），不同年度比较，差异无统计学意义（P>0.05）。（2）多因素回归分析结果显示，孕妇高龄、经产妇、妊娠前超重及肥胖、妊娠期增重过多、GDM及妊娠早期三酰甘油水平≥1.7 mmol/L均与LGA的发生风险显著相关（P均<0.05）。其中妊娠前超重及肥胖、妊娠期增重过多及经产妇是3个年度均存在的危险因素，在2017年度则未发现GDM与LGA相关。（3）随着年份的增加，各因素的人群对LGA风险的PAR%变化趋势为，妊娠期增重过多的PAR%逐渐下降（2011、2014及2017年分别为32.6%、27.2%、22.2%），而妊娠前超重及肥胖的PAR%上升（4.2%、3.3%、8.4%），经产妇导致的PAR%也呈上升趋势（3.5%、6.3%、15.9%）。（4）不同年度，孕妇妊娠早、中期增重对LGA的PAR%较高，2014、2017年分别为20.2%、19.0%。 结论： 妊娠期增重过多、妊娠前超重及肥胖、经产妇，是LGA发生的重要影响因素。近年，妊娠期增重对LGA的人群归因危险度比例有所下降，但妊娠早、中期增重仍是重要的归因因素之一。合理的妊娠前及妊娠早、中期体重管理，对降低LGA的发生风险有重要意义。.